content: /* Copyright (C) 2016-2018 Alibaba Group Holding Limited
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  ==============================================================================*/
  
  // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf;
  
  import java.util.Collection;
  import java.util.List;
  
  /**
   * An interface extending {@code List<String>} that also provides access to the
   * items of the list as UTF8-encoded ByteString or byte[] objects. This is
   * used by the protocol buffer implementation to support lazily converting bytes
   * parsed over the wire to String objects until needed and also increases the
   * efficiency of serialization if the String was never requested as the
   * ByteString or byte[] is already cached. The ByteString methods are used in
   * immutable API only and byte[] methods used in mutable API only for they use
   * different representations for string/bytes fields.
   *
   * @author jonp@google.com (Jon Perlow)
   */
  public interface LazyStringList extends ProtocolStringList {
  
    /**
     * Returns the element at the specified position in this list as a ByteString.
     *
     * @param index index of the element to return
     * @return the element at the specified position in this list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index >= size()})
     */
    ByteString getByteString(int index);
  
    /**
     * Returns the element at the specified position in this list as an Object
     * that will either be a String or a ByteString.
     *
     * @param index index of the element to return
     * @return the element at the specified position in this list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index >= size()})
     */
    Object getRaw(int index);
  
    /**
     * Returns the element at the specified position in this list as byte[].
     *
     * @param index index of the element to return
     * @return the element at the specified position in this list
     * @throws IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index >= size()})
     */
    byte[] getByteArray(int index);
  
    /**
     * Appends the specified element to the end of this list (optional
     * operation).
     *
     * @param element element to be appended to this list
     * @throws UnsupportedOperationException if the <tt>add</tt> operation
     *         is not supported by this list
     */
    void add(ByteString element);
  
    /**
     * Appends the specified element to the end of this list (optional
     * operation).
     *
     * @param element element to be appended to this list
     * @throws UnsupportedOperationException if the <tt>add</tt> operation
     *         is not supported by this list
     */
    void add(byte[] element);
  
    /**
     * Replaces the element at the specified position in this list with the
     * specified element (optional operation).
     *
     * @param index index of the element to replace
     * @param element the element to be stored at the specified position
     * @throws UnsupportedOperationException if the <tt>set</tt> operation
     *         is not supported by this list
     *         IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index >= size()})
     */
    void set(int index, ByteString element);
    
    /**
     * Replaces the element at the specified position in this list with the
     * specified element (optional operation).
     *
     * @param index index of the element to replace
     * @param element the element to be stored at the specified position
     * @throws UnsupportedOperationException if the <tt>set</tt> operation
     *         is not supported by this list
     *         IndexOutOfBoundsException if the index is out of range
     *         ({@code index < 0 || index >= size()})
     */
    void set(int index, byte[] element);
  
    /**
     * Appends all elements in the specified ByteString collection to the end of
     * this list.
     *
     * @param c collection whose elements are to be added to this list
     * @return true if this list changed as a result of the call
     * @throws UnsupportedOperationException if the <tt>addAllByteString</tt>
     *         operation is not supported by this list
     */
    boolean addAllByteString(Collection<? extends ByteString> c);
  
    /**
     * Appends all elements in the specified byte[] collection to the end of
     * this list.
     *
     * @param c collection whose elements are to be added to this list
     * @return true if this list changed as a result of the call
     * @throws UnsupportedOperationException if the <tt>addAllByteArray</tt>
     *         operation is not supported by this list
     */
    boolean addAllByteArray(Collection<byte[]> c);
  
    /**
     * Returns an unmodifiable List of the underlying elements, each of which is
     * either a {@code String} or its equivalent UTF-8 encoded {@code ByteString}
     * or byte[]. It is an error for the caller to modify the returned
     * List, and attempting to do so will result in an
     * {@link UnsupportedOperationException}.
     */
    List<?> getUnderlyingElements();
  
    /**
     * Merges all elements from another LazyStringList into this one. This method
     * differs from {@link #addAll(Collection)} on that underlying byte arrays are
     * copied instead of reference shared. Immutable API doesn't need to use this
     * method as byte[] is not used there at all.
     */
    void mergeFrom(LazyStringList other);
  
    /**
     * Returns a mutable view of this list. Changes to the view will be made into
     * the original list. This method is used in mutable API only.
     */
    List<byte[]> asByteArrayList();
  
    /** Returns an unmodifiable view of the list. */
    LazyStringList getUnmodifiableView();
  }
  